Heretofore, a thermoelement for displacing a displacement means such as a shaft and a thermovalve in which the thermoelement is incorporated has been proposed, in which attention is focused on an expansive action of a thermosensitive fluid caused by a rise in the ambient temperature.
In Japanese Laid-Open Patent Publication No. 07-006675, an invention referred to as an “ampblock system wax type thermostat” is disclosed. According to the disclosure of Japanese Laid-Open Patent Publication No. 07-006675, a structure is revealed in which a wax 2, which is enclosed in a temperature sensing part 1, expands accompanying a rise in the ambient temperature, whereby a diaphragm 3 flexes and rises upwardly. As a result, solid particulate matter 18, which is housed in an amp space 16, rises and is displaced to thereby displace a piston 5.
An invention referred to as a “thermo-actuator” is disclosed in Japanese Laid-Open Patent Publication No. 09-089153. According to such a “thermo-actuator,” a wax 11 fills a space between a rubber seal spool 5 and a thermosensitive cylinder 9. In a state in which the thermosensitive cylinder 9 is cooled, the wax 11 shrinks upon solidification thereof, and since the area occupied by the wax 11 is reduced, a rubber seal straight pipe 3 is pressed under a spring load and is compressed in a bellows-like shape, whereby a rod 2 is pressed deeply into the rubber seal spool 5 to occupy an initial position. When the thermosensitive cylinder 9 reaches a predetermined temperature accompanying a rise in the ambient temperature, the wax 11 inside the thermosensitive cylinder 9 expands and the pressure thereof increases, so that as the seal spool 5 becomes flattened, the rod 2 is squeezed upwardly, and thus the bellows 3 rises and is restored to the form of a straight pipe.
An invention referred to as a “thermovalve” is disclosed in Japanese Laid-Open Patent Publication No. 2005-180461. According to this invention, a thermovalve 4 is inserted and arranged along an axial direction of a lubricating oil inlet 1. When the lubricating oil that flows through the lubricating oil inlet 1 rises to a predetermined temperature, a thermally actuated member 6a inside a thermoelement 6 that makes up the thermovalve 4 expands, whereby a rod 6b is pushed out and presses down a valve plug 7, and the lubricating oil is allowed to flow into an oil cooler from a lubricating oil outlet 2.